1const { Buffer } = require('buffer');
2const fs = require("fs");
3const path = require("path");
4const { once } = require('events');
5
6const prettierContainerPath = process.argv[2];
7if (prettierContainerPath == null || prettierContainerPath.length == 0) {
8 process.stderr.write(`Prettier path argument was not specified or empty.\nUsage: ${process.argv[0]} ${process.argv[1]} prettier/path\n`);
9 process.exit(1);
10}
11fs.stat(prettierContainerPath, (err, stats) => {
12 if (err) {
13 process.stderr.write(`Path '${prettierContainerPath}' does not exist\n`);
14 process.exit(1);
15 }
16
17 if (!stats.isDirectory()) {
18 process.stderr.write(`Path '${prettierContainerPath}' exists but is not a directory\n`);
19 process.exit(1);
20 }
21});
22const prettierPath = path.join(prettierContainerPath, 'node_modules/prettier');
23
24class Prettier {
25 constructor(path, prettier, config) {
26 this.path = path;
27 this.prettier = prettier;
28 this.config = config;
29 }
30}
31
32(async () => {
33 let prettier;
34 let config;
35 try {
36 prettier = await loadPrettier(prettierPath);
37 config = await prettier.resolveConfig(prettierPath) || {};
38 } catch (e) {
39 process.stderr.write(`Failed to load prettier: ${e}\n`);
40 process.exit(1);
41 }
42 process.stderr.write(`Prettier at path '${prettierPath}' loaded successfully, config: ${config}\n`);
43 process.stdin.resume();
44 handleBuffer(new Prettier(prettierPath, prettier, config));
45})()
46
47async function handleBuffer(prettier) {
48 for await (let messageText of readStdin()) {
49 let message;
50 try {
51 message = JSON.parse(messageText);
52 } catch (e) {
53 sendResponse(makeError(`Failed to parse message '${messageText}': ${e}`));
54 continue;
55 }
56 handleMessage(message, prettier).catch(e => {
57 sendResponse({ id: message.id, ...makeError(`error during message handling: ${e}`) });
58 });
59 }
60}
61
62const headerSeparator = "\r\n";
63const contentLengthHeaderName = 'Content-Length';
64
65async function* readStdin() {
66 let buffer = Buffer.alloc(0);
67 let streamEnded = false;
68 process.stdin.on('end', () => {
69 streamEnded = true;
70 });
71 process.stdin.on('data', (data) => {
72 buffer = Buffer.concat([buffer, data]);
73 });
74
75 async function handleStreamEnded(errorMessage) {
76 sendResponse(makeError(errorMessage));
77 buffer = Buffer.alloc(0);
78 messageLength = null;
79 await once(process.stdin, 'readable');
80 streamEnded = false;
81 }
82
83 try {
84 let headersLength = null;
85 let messageLength = null;
86 main_loop: while (true) {
87 if (messageLength === null) {
88 while (buffer.indexOf(`${headerSeparator}${headerSeparator}`) === -1) {
89 if (streamEnded) {
90 await handleStreamEnded('Unexpected end of stream: headers not found');
91 continue main_loop;
92 } else if (buffer.length > contentLengthHeaderName.length * 10) {
93 await handleStreamEnded(`Unexpected stream of bytes: no headers end found after ${buffer.length} bytes of input`);
94 continue main_loop;
95 }
96 await once(process.stdin, 'readable');
97 }
98 const headers = buffer.subarray(0, buffer.indexOf(`${headerSeparator}${headerSeparator}`)).toString('ascii');
99 const contentLengthHeader = headers.split(headerSeparator).map(header => header.split(':'))
100 .filter(header => header[2] === undefined)
101 .filter(header => (header[1] || '').length > 0)
102 .find(header => header[0].trim() === contentLengthHeaderName);
103 if (contentLengthHeader === undefined) {
104 await handleStreamEnded(`Missing or incorrect ${contentLengthHeaderName} header: ${headers}`);
105 continue main_loop;
106 }
107 headersLength = headers.length + headerSeparator.length * 2;
108 messageLength = parseInt(contentLengthHeader[1], 10);
109 }
110
111 while (buffer.length < (headersLength + messageLength)) {
112 if (streamEnded) {
113 await handleStreamEnded(
114 `Unexpected end of stream: buffer length ${buffer.length} does not match expected header length ${headersLength} + body length ${messageLength}`);
115 continue main_loop;
116 }
117 await once(process.stdin, 'readable');
118 }
119
120 const messageEnd = headersLength + messageLength;
121 const message = buffer.subarray(headersLength, messageEnd);
122 buffer = buffer.subarray(messageEnd);
123 messageLength = null;
124 yield message.toString('utf8');
125 }
126 } catch (e) {
127 sendResponse(makeError(`Error reading stdin: ${e}`));
128 } finally {
129 process.stdin.off('data', () => { });
130 }
131}
132
133// TODO kb, more methods?
134// shutdown
135// error
136async function handleMessage(message, prettier) {
137 const { method, id, params } = message;
138 if (method === undefined) {
139 throw new Error(`Message method is undefined: ${JSON.stringify(message)}`);
140 }
141 if (id === undefined) {
142 throw new Error(`Message id is undefined: ${JSON.stringify(message)}`);
143 }
144
145 if (method === 'prettier/format') {
146 if (params === undefined || params.text === undefined) {
147 throw new Error(`Message params.text is undefined: ${JSON.stringify(message)}`);
148 }
149 if (params.options === undefined) {
150 throw new Error(`Message params.options is undefined: ${JSON.stringify(message)}`);
151 }
152
153 let resolvedConfig = {};
154 if (params.options.filepath !== undefined) {
155 resolvedConfig = await prettier.prettier.resolveConfig(params.options.filepath) || {};
156 }
157
158 const options = {
159 ...(params.options.prettierOptions || prettier.config),
160 ...resolvedConfig,
161 parser: params.options.parser,
162 plugins: params.options.plugins,
163 path: params.options.filepath
164 };
165 process.stderr.write(`Resolved config: ${JSON.stringify(resolvedConfig)}, will format file '${params.options.filepath || ''}' with options: ${JSON.stringify(options)}\n`);
166 const formattedText = await prettier.prettier.format(params.text, options);
167 sendResponse({ id, result: { text: formattedText } });
168 } else if (method === 'prettier/clear_cache') {
169 prettier.prettier.clearConfigCache();
170 prettier.config = await prettier.prettier.resolveConfig(prettier.path) || {};
171 sendResponse({ id, result: null });
172 } else if (method === 'initialize') {
173 sendResponse({
174 id,
175 result: {
176 "capabilities": {}
177 }
178 });
179 } else {
180 throw new Error(`Unknown method: ${method}`);
181 }
182}
183
184function makeError(message) {
185 return {
186 error: {
187 "code": -32600, // invalid request code
188 message,
189 }
190 };
191}
192
193function sendResponse(response) {
194 let responsePayloadString = JSON.stringify({
195 jsonrpc: "2.0",
196 ...response
197 });
198 let headers = `${contentLengthHeaderName}: ${Buffer.byteLength(responsePayloadString)}${headerSeparator}${headerSeparator}`;
199 let dataToSend = headers + responsePayloadString;
200 process.stdout.write(dataToSend);
201}
202
203function loadPrettier(prettierPath) {
204 return new Promise((resolve, reject) => {
205 fs.access(prettierPath, fs.constants.F_OK, (err) => {
206 if (err) {
207 reject(`Path '${prettierPath}' does not exist.Error: ${err}`);
208 } else {
209 try {
210 resolve(require(prettierPath));
211 } catch (err) {
212 reject(`Error requiring prettier module from path '${prettierPath}'.Error: ${err}`);
213 }
214 }
215 });
216 });
217}